Bobby Isaac

Isaac abruptly retired from full-time top-level competition in 1973 and died of a heart attack during a late model race at Hickory Motor Speedway in 1977.

Isaac won 37 races in NASCAR's top series during his career, including 11 in his championship season, and started from the pole position 49 times.

Isaac dropped out of the 1973 Talladega 500 mid-race in an impulsive decision which surprised his pit crew and the team owner.

On Saturday night, August 13, 1977, while running fourth, Isaac pulled out of the Winston 200 late model sportsman race at Hickory Motor Speedway with 40 laps left, and called for a relief driver, collapsing on pit road of heat exhaustion.

Weather reports for the area that day showed temperatures which had reached 91 °F (33 °C) at mid-afternoon, and were still around 80 °F (27 °C) at the time of Isaac's collapse.

[7] Though Isaac was revived briefly at the hospital and was conversing with friends, he later died from a heart attack caused by heat exhaustion, at 12:45 a.m. on August 14, 13 days after his 45th birthday.

[8][9] Details of Isaac's pit lane collapse on the night of his death were given to reporters by friend and former racing driver Ned Jarrett.

Jarrett asserted at that time that the reason Isaac left the 1973 Talladega 500 was because he "had heard a voice that told him to quit".